Chapter 3 Percents Percents Definition per cent percent

Chapter 3 - Percents

Percents - Definition per cent percent out of 100 for every

Percents 25% 25 100 1 4

Percents n 7% commission rate. 7 100 You will earn $7 for every $100 of sales.

Percents – Conversion to other Forms 65%

Convert Percents to Decimals 25% Convert a Percent to Decimal Form: 18%. 1. 25% . 0125 201% 2. 01

Convert Decimals to Percents 50% Convert a Decimal to Percent Form: 0. 38 % 0. 38 0. 4% 0. 004 300% 3

Practice - % to Decimal One More!!!

Practice n Ch 3, Section 1 – Writing Decimals and Fractions as Percents Textbook Exercise 3. 1 (pages 91 – 92) _____ #3 – 15 (odd numbered problems only) _____ #18 – 30 (odd numbered problems only) _____ #33 – 39 (odd numbered problems only)

The Components of a Percent Problem

Components B, P, R n Base n Part n Rate In the 12: 30 Applied Math class, there are 22 students. 17 of them, or about 77%, are in the Welding Program.

Components B, P, R n Base n Part n Rate Dave is a salesperson paid on a commission rate of 7%. Last week his weekly sales were $21, 500, so he earned $1, 505.

Components B, P, R n Base Part n Rate Base 45 is 90% of 50.

Practice n n WORKSHEETS _____ (Practice Set 3 -2) Identify Part, Base, and Rate. _____ (Practice Set 3 -3) Identify Part, Base, and Rate in “Generic Problems”. _____ (Practice Set 3 -4) Identify the component (P, B, or R) that needs to be Solved.

Solving Percent Problems

Percent Formula One formula for everything: Part P Base B = Rate R 100

Solve Percent Problems 1 of 3 20% of U. S. cars are blue. If there 135 cars in the Bldg 100 lot, how many are blue? Part P 135 Base = 20 Rate 100 135 x 20 = 2700 ÷ 100 = 27 blue cars

Solve Percent Problems 2 of 3 At a job interview, a machinist was given a basic skills test. His results were 30 correct out of 35 possible. What is his score expressed as a percent? Part 30 35 Base = Rate R 100 30 x 100 = 3000 ÷ 35 = 85. 7% correct

Solve Percent Problems 3 of 3 On a day when it snowed heavily, 33 people, which is 55% of a company’s total workforce made it to work on-time. What is the size of the company’s workforce? Part 33 B Base = Rate 55 100 33 x 100 = 3300 ÷ 55 = 60 people

Solve Percent Problems Generic 1 of 1 Rate Base Part 18% of what number is 900? Part 900 B Base = Rate 18 100 900 x 100 = 90, 000 ÷ 18 = 5000

Practice n n n WORKSHEET _____(Practice Set 3 -5) Introduction to Solving Percent Problems (#1 – 30 odd numbered problems)

Select Problems from Ch 3 Sections 2 through 4 CHAPTER 3 PERCENT

Practice n Ch 3, Section 2 – Finding the Part Textbook Exercise 3. 2 (pages 97 – 99) _____ #18, 19, 20, 29, 30, 31, 35 n Ch 3, Section 3 – Finding the Base Textbook Exercise 3. 3 (pages 103 – 104) _____ #28, 30, 31, 34, 35 n Ch 3, Section 4 – Finding the Rate Textbook Exercise 3. 4 (pages 109 – 110) _____ #22, 24, 25

Ch 3 Section 2 #19 page 97 n 19. ) i. Phone priced at $399. Sales tax rate is 7. 75%. Find the total purchase price. Part P 399 Base = Rate 7. 75 100 399 x 7. 75 = 3092. 25 ÷ 100 = 30. 9225 Tax = $30. 92 Total Purchase Price = $399 + $30. 92 Total Purchase Price = $429. 92

Ch 3 Section 3 #31 page 104 n Jim’s income spending: q q q q n $266. 50 28% housing 15% food 11% clothing 15% transportation 11% education 7% recreation The rest is savings. If his savings are $266. 50 per month, what is his monthly earnings? Part $266. 50 B Base 100% 13% - (28%+15%+11% +7%) = Rate 13 100 266. 50 x 100 = 26, 650 ÷ 13 = $2050

Ch 3 Section 3 #34 page 104 n Nortel will be laying-off 4, 000 employees which is 4% of their workforce. n How many workers will remain after the layoffs? 4, 000 Part B Base = Rate 4 100 4, 000 x 100 = 400, 000 ÷ 4 = 100, 000 original workforce 100, 000 – 4, 000 = 96, 000 remain

Ch 3 Section 4 #25 page 110 n What percent of the total advertising budget is spent on radio advertising? Newspaper $2250 Television $1425 Radio $954 Yellow Pages $1605 Outdoor $1950 Misc. $2775 Game Plan: In order to get RATE, I must know the PART and the BASE: $2250 $1425 $954 $1605 $1950 + $2775 $10, 959 Part 954 Base 10, 959 = Rate R 100 954 x 100 = 95, 400 ÷ 10, 959 = 8. 7% (radio)

Percent Change Percent Increase Percent Decrease

Overview n Sample Problem 1 Gas Prices q q Last Week: $3. 68 This Week: $3. 75 – 3. 68 Amount of Increase ($) Part 0. 07 Base 3. 68 What is the percent increase in the price of gas? = Rate % Increase 100 Original Value “(B)efore number” 1. 9% Inc.

Overview n Sample Problem 2 Work Truck: Miles Driven q q Last Year: 28, 900 miles This Year: 23, 150 miles 28, 900 – 23, 150 Amount of Decrease (miles) Part 5, 750 28, 900 Base What is the percent decrease in the miles driven? = Rate % Decrease 100 Original Value “(B)efore number” 19. 9% Dec.

Percent Change P B = Amt of P Change = “Before” B Number R 100 R Percent Change 100

Practice n n WORKSHEET _____ (Practice Set 3 -6) Determine Percent Change

Part II - Practice Test n n Practice Test Ch 3 Test (pages 127 -128) _____ #1 – 20 (skip #17, 18 and 20) Scoring Criteria for Practice Test: All required problems completed. Process (solution method shown) for all problems except multiple choice or fill-in-the-blank ones. Score 5 5 4 3 2 1 0 _____ / 10